RESUMEN
Novel biological adhesives made from chitin derivatives were prepared and evaluated for their adhesive properties and biocompatibility. Chitin derivatives with acrylic groups, such as 2-hydroxy-3-methacryloyloxypropylated carboxymethyl chitin (HMA-CM-chitin), were synthesized and cured by the addition of an aqueous hydrogen peroxide solution as a radical initiator. The adhesive strength of HMA-CM-chitin increased when it was blended with chitin nanofibers (CNFs) or surface-deacetylated chitin nanofibers (S-DACNFs). HMA-CM-chitin/CNFs or HMA-CM-chitin/S-DACNFs have almost equal adhesive strength compared to that of a commercial cyanoacrylate adhesive. Moreover, quick adhesion and induction of inflammatory cells migration were observed in HMA-CM-chitin/CNF and HMA-CM-chitin/S-DACNF. These findings indicate that the composites prepared in this study are promising materials as new biological adhesives.
Asunto(s)
Adhesivos/farmacología , Quitina/análogos & derivados , Nanofibras/química , Animales , Quitina/química , Quitina/farmacología , Cianoacrilatos/química , Femenino , Recuento de Leucocitos , Ensayo de Materiales , Metacrilatos/química , Presión , Ratas Wistar , Resistencia a la Tracción/efectos de los fármacosRESUMEN
Fucoidan and chondroitin sulfate, which are well known sulfated polysaccharides, were depolymerized under hydrothermal conditions (120-180°C, 5-60min) as a method for the preparation of sulfated polysaccharides with controlled molecular weights. Fucoidan was easily depolymerized, and the change of the molecular weight values depended on the reaction temperature and time. The degree of sulfation and IR spectra of the depolymerized fucoidan did not change compared with those of untreated fucoidan at reaction temperatures below 140°C. However, fucoidan was partially degraded during depolymerization above 160°C. Nearly the same depolymerization was observed for chondroitin sulfate. These results indicate that hydrothermal treatment is applicable for the depolymerization of sulfated polysaccharides, and that low molecular weight products without desulfation and deformation of the initial glycan structures can be obtained under mild hydrothermal conditions.
Asunto(s)
Sulfatos de Condroitina/química , Calor , Polisacáridos/químicaRESUMEN
Nuclear factor-kappaB (NF-κB) is critical for the expression of multiple genes involved in inflammatory responses and cellular survival. NF-κB is normally sequestered in the cytoplasm through interaction with an inhibitor of NF-κB (IκB), but inflammatory stimulation induces proteasomal degradation of IκB, followed by NF-κB nuclear translocation. The degradation of IκB is mediated by a SCF (Skp1-Cullin1-F-box protein)-type ubiquitin ligase complex that is post-translationaly modified by a ubiquitin-like molecule Nedd8. In this study, we report that BRCA1-associated protein 2 (Brap2) is a novel Nedd8-binding protein that interacts with SCF complex, and is involved in NF-κB translocation following TNF-α stimulation. We also found a putative neddylation site in Brap2 associated with NF-κB activity. Our findings suggest that Brap2 is a novel modulator that associates with SCF complex and controls TNF-α-induced NF-κB nuclear translocation.
Asunto(s)
Inflamación/metabolismo , FN-kappa B/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Secuencia de Aminoácidos , Línea Celular , Núcleo Celular/metabolismo , Proteínas Cullin/metabolismo , Humanos , Modelos Biológicos , Datos de Secuencia Molecular , Proteína NEDD8 , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Multimerización de Proteína , Transporte de Proteínas/efectos de los fármacos , Alineación de Secuencia , Factor de Necrosis Tumoral alfa/farmacología , Ubiquitina-Proteína Ligasas/química , Ubiquitinas/metabolismoRESUMEN
We evaluated the anti-tumor activities of the oral administration of fucoidan extracted from Cladosiphon okamuranus using a tumor (colon 26)-bearing mouse model. The materials used included low-molecular-weight fucoidan (LMWF: 6.5-40 kDa), intermediate-molecular-weight fucoidan (IMWF: 110-138 kDa) and high-molecular-weight fucoidan (HMWF: 300-330 kDa). The IMWF group showed significantly suppressed tumor growth. The LMWF and HMWF groups showed significantly increased survival times compared with that observed in the control group (mice fed a fucoidan-free diet). The median survival times in the control, LMWF, IMWF and HMWF groups were 23, 46, 40 and 43 days, respectively. It was also found that oral administration of fucoidan increased the population of natural killer cells in the spleen. Furthermore, from the results of the experiment using Myd-88 knockout mice, it was found that these effects are related to gut immunity. These results suggest that fucoidan is a candidate anti-tumor functional food.
Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Phaeophyceae/química , Polisacáridos/farmacología , Administración Oral , Animales , Antineoplásicos Fitogénicos/administración & dosificación , Neoplasias del Colon/prevención & control , Femenino , Etiquetado Corte-Fin in Situ , Células Asesinas Naturales/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Factor 88 de Diferenciación Mieloide/genética , Factor 88 de Diferenciación Mieloide/metabolismo , Polisacáridos/administración & dosificación , BazoRESUMEN
Technical advances in myocutaneous flap preparation have resulted in primary reconstruction now being generally indicated for malignant tumors extensively infiltrating the pelvic cavity and perineum. Pelvic tumor resection can dramatically improve the health-related quality of life (QOL) of patients with locally recurrent rectal cancer complicated by infection and pain. However, the removal of a wide area of perineum by these two procedures often leaves a large dead space. A gluteal thigh muscle, rectus abdominis muscle, or pedicle myocutaneous flap is usually made to reconstruct such extensive perineal defects. The subject of this case report was a 76-year-old woman with recurrent rectal cancer in the pelvis after abdominoperineal resection. The large pelvic tumor, which was causing severe pain, was resected and the extensive perineal defects were reconstructed using a modified maximus V-Y advancement flap. The operating time was approximately 30 min, and the pain after surgery was much less severe. Moreover, she could walk the day after surgery and returned to normal daily life without requiring prolonged bed rest. No infection developed in the intrapelvic dead space postoperatively. This technique proved very useful for improving the patient's QOL.